Eliminate target hook IsEligibleForTailCallOptimization.

Target independent isel should always pass along the "tail call" property. Change
target hook LowerCall's parameter "isTailCall" into a refernce. If the target
decides it's impossible to honor the tail call request, it should set isTailCall
to false to make target independent isel happy.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94626 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/Alpha/AlphaISelLowering.h b/lib/Target/Alpha/AlphaISelLowering.h
index b204faf..0f17025 100644
--- a/lib/Target/Alpha/AlphaISelLowering.h
+++ b/lib/Target/Alpha/AlphaISelLowering.h
@@ -121,7 +121,7 @@
 
     virtual SDValue
       LowerCall(SDValue Chain, SDValue Callee,
-                CallingConv::ID CallConv, bool isVarArg, bool isTailCall,
+                CallingConv::ID CallConv, bool isVarArg, bool &isTailCall,
                 const SmallVectorImpl<ISD::OutputArg> &Outs,
                 const SmallVectorImpl<ISD::InputArg> &Ins,
                 DebugLoc dl, SelectionDAG &DAG,